This invention relates to a substantially solvent-free adhesive composition to the use of such an adhesive composition, in particular the use of such an adhesive composition in the form of a sheet, tape, film or the like to bond a polymeric layer to at least a portion of an elongate substrate or substrates.
Dimensionally recoverable articles such as a tubular and wraparound sleeves are well known for use in enclosing an elongate substrate such as pipes or cables and, in particular, cable joints or splices. The dimensionally recoverable sleeve can be a dimensionally heat-recoverable sleeve and can be sealed to the substrate, if desired, using a mastic or hot melt adhesive.
Dimensionally recoverable articles which do not require heat to effect recovery are also well known. Such articles are typically formed of an elastomeric sheet or tube held in an expanded state by a restraining means which can be removed or separated from the elastomeric member to permit it to recover to the unexpanded state. Such articles are also used to enclose elongate substrates and it is also desirable that the recovered article be sealed to the substrate. Generally, contact adhesives have been used for this purpose. The contact adhesive is a solvent based adhesive which can be placed on at least part of the substrate, generally before the recoverable sleeve is placed in position about the substrate. The contact adhesive can be coated on the interior surface of the sleeve, but this has been found not to be practical. Solvent based contact adhesive used in this manner and applied to the substrate only provides a relatively weak adhesive bond. Further, the adhesive has a paste-like consistency making it difficult to apply it uniformly to the substrate. Non-uniform application can lead to inadequate sealing of the recovered sleeve to the substrate. This in turn creates leak paths through which water can migrate. This is particularly undesirable when the substrate enclosed by the sleeve is a joint between electric cables.
This invention provides an adhesive composition which can be in the form of a tape, sheet, film or sleeve for convenient application to an elongate substrate. The flow and adhesive characteristics of the adhesive composition make it particularly suitable for use with a dimensionally recoverable sleeve to seal the recovered sleeve to the substrate.